number of human T--T hybridomas were developed which secreted variety of immunoregulatory factors including B cell growth actor (BCGF), B cell differentiation factor (BCDF) and various uppressor factors. In addition, a number of T cell lines were dentified and propogated which secreted similar BCGFs and CDFs. These lines serve as excellent sources of virtually nlimited quantities of homogeneous factors which can be urified, amino acid sequenced, and ultimately used in studies imed at cloning the genes for these factors. Further studies re directed at defining the nature of the growth factor eceptors on the target cells in question. The original bservation that certain human B cell lines secreted their own CGF and/or BCDF was made and the factors were precisely haracterized. We have also developed panels of soluble ntigen-specific human T cell clones which grow independently f exogenous factors. Upon stimulation with the appropriate ntigen, these antigen-specific clones secrete multiple ymphokines including IL-2, BCGF, BCDF, and interferon. We nfected an antigen-specific T cell clone with human T cell eukemia/lymphoma virus (HTLV). HTLV infection converted the lone from a truly antigen-specific, major histocompatibility omplex (MHC)-restricted inducer of B cell function to a line hich indiscriminantly induced polyclonal Ig production in an HC-nonrestricted manner. Clonal studies of T cells from atients with the acquired immunodeficiency syndrome (AIDS) ere performed, and it was demonstrated that AIDS patients have arkedly decreased cloning efficiency of both T4 helper/inducer) and T8 (cytotoxic/suppressor) subsets. owever, the subsets that were in fact clonable functioned ormally. B cell lines from patients with inherited disorders f phagocytosis were developed and characterized making vailable unlimited numbers of cloned cells for biochemical and enetic study.